1. Field of the Invention
The invention relates to a clock generator, and more particularly to a clock generator of a Universal Serial Bus (USB) module.
2. Description of the Related Art
A Universal Serial Bus (USB) is a serial bus standard for external apparatus connection, providing hot plug, plug and play and other related functions.
Currently, the USB 2.0 standard provides three transfer rates: low-speed, full-speed, and high-speed transfer rates, which support: 1.5 Mbps; 12 Mbps; and 480 Mbps data rates, respectively. However, even faster transfer rates are being demanded for electronic apparatuses, due to continued advanced technological development, so that the electronic apparatuses may quickly access data from external apparatuses and subsequently perform related operations.
Therefore, a next generation USB industry-standard, the USB 3.0 standard, was established by the USB Implementers Forum. The USB 3.0 standard allows employment of SuperSpeed data transfer and non-SuperSpeed (i.e. USB 2.0) data transfer simultaneously, wherein SuperSpeed data transfer supports up to a 5 Gbps data rate.